Centrifugal atomizer is one of the widely used dryers in industrial production. The feed liquid is added to the high-speed rotating dispersion disc, and the liquid is shaken into droplets by centrifugal force. Then it is dried in the dryer. On the surface of the dispersion plate, the liquid spreads as a thin film and is thrown around the circumference at high speed. The atomization effect depends on the circumferential linear velocity and the feed speed, and is also related to some physical properties of the feed liquid and other factors.
Centrifugal atomizer; principle of operation
Working principle of centrifugal atomizer system:Different from pressure spray drying system. It uses a centrifugal disc atomizer. The centrifugal disc atomizer is installed in the upper part of the spray tower. The mud pump sends the mud to be dried into the high level tank at the top of the tower at a certain height. Under the action of gravity, the mud flows naturally from the high level tank into the center of the centrifugal disk atomizer in the tower through the slurry discharge pipe. The centrifugal disk is driven by the motor and rotates at a high speed of 4000 ~ 20000 r/min. When the slurry flows to the edge through the channel or nozzle on the centrifugal disk, it will acquire a high tangential linear velocity. Once it leaves the centrifugal disc, it is immediately torn by air friction,. It is atomized into mud droplets. The hot air discharged from the air heater is sent to the hot air distribution chamber at the top of the tower, through the hot air duct. It comes into contact with the mud droplets downstream and dries the mud into a powder suitable for dry press molding. The powder is then dropped to the lower part of the spray tower cone. The dry exhaust gas is extracted from the exhaust port located in the lower part of the cone, the fine powder is recovered by the dust collector, and the purified gas is discharged into the atmosphere by the exhaust fan.
Centrifugal atomizer; characteristics
The characteristics of the centrifugal spray dryer are basically determined by the characteristics of the atomizer
(1) Centrifugal spray drying does not require strict filtration equipment. If there is no fibrous liquid in the feed liquid. The material-liquid channels are basically not blocked.
(2) Can accommodate higher viscosity liquids (compared to pressure spray drying).
(3) It is easier to empty the product particle size, because the atomizer speed is easy to adjust. Narrow particle size distribution.
(4)When adjusting the processing volume, it is not necessary to change the working state of the atomizer,. The same product can be obtained when the feed volume is varied within 25%.
(5) Since the fog mass produced by the centrifugal atomizer is basically on the same level. , the droplets move along a combination of radial and tangential directions with almost no axial initial velocity, so the diameter of the dryer is relatively large. (b) The small diameter to length ratio allows the use of space within the drying chamber.
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